At present, medium and large tonnage wheeled cranes are applied more and more widely, and the lifting capability has been improved continuously, resulting in larger and larger self weights of the cranes, which are far more than the stringent requirements on the total weights and axle loads of the cranes. Therefore, in order to comply with this transportation requirement of the wheeled cranes, the most basic operating devices are only carried at a general running state, and other devices need to be demounted and transported separately. In order to ensure rapid transfer, quick and simple assembly and fast operation of the wheeled cranes, the mounting and demounting of the separate transported devices must be simple and convenient, and the purpose of rapid demounting and mounting is achieved while minimizing the time, manpower and material resources.
A combined counterweight is a device, which is widely used in the medium and large tonnage wheeled cranes, needs to be transported separately and aims at improving the lifting performance of the cranes on medium and long arms and on large amplitudes and giving full play to the performance of lifting arms and other main structural members. When the cranes are on the road, the combined counterweight needs to be demounted to meet relevant requirements and needs to be demounted and mounted once each time when the cranes are transferred for a long distance, therefore a method must be found for frequently mounting and demounting the combined counterweight with fast and convenient operation and without relying on auxiliary equipment.
Currently, the counterweight of the wheeled crane is mainly hitched in such a manner that after a piston rod of a lifting oil cylinder stretches into a hitching hole, the lifting oil cylinder is driven by a turntable to rotate to enable a hitching platform at the lower end of the piston rod to enter a hitching platform groove, and the oil cylinder retracts to mount the combined counterweight. After the piston rod enters the hitching hole, the hitching platform at the lower end of the piston rod needs to enter the hitching platform groove, which requires the whole upperstructure of the wheeled crane to rotate, so that the mounting space is large and the working efficiency is low. Meanwhile, to accurately locate the lifting oil cylinder and the mounting hole, a plurality of position detecting devices need to be provided, otherwise at least two operators need to cooperate to mount and demount the counterweight. In addition, in the existing technical solutions, the hitching platform at the lower end of the piston rod is in rigid connection with the piston rod, and the counterweight is located by the oil cylinder, when the counterweight swings slightly, the piston rod bears an offset load force and is subjected to an oil leakage phenomenon or even subjected to failure and breakage if working for a long time.